Bees and Hummingbirds Consume Small Amounts of Alcohol in Nectar

Study finds ethanol in nectar of many flowers, with birds and insects ingesting similar amounts to a daily alcoholic drink for humans.

Mar. 27, 2026 at 7:00pm

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Researchers at the University of California, Berkeley, have found that the nectar of many flowers contains small amounts of alcohol, with bees, hummingbirds, and other nectar-feeding animals consuming these trace amounts as they feed. While the alcohol levels are low, the researchers say it may still affect animal behavior in subtle ways, though the animals do not appear to get intoxicated.

Why it matters

This study provides new insights into the relationship between plants, pollinators, and alcohol consumption in nature. It raises questions about how animals have adapted to the ubiquity of dietary alcohol and how it may influence their behavior, even at low levels. The findings could have implications for understanding plant-pollinator dynamics and the evolution of tolerance to alcohol in different species.

The details

The researchers tested the nectar of 29 plant species and found ethanol, a type of alcohol, in 26 of them. Most samples only had tiny amounts, but one reached 0.056% ethanol by weight, about 0.1 proof. The alcohol likely forms when yeast ferments sugar in the nectar. While small, nectar is the main food source for many species, and hummingbirds in particular can consume 50-150% of their body weight in nectar per day. This means they may ingest about 0.2 grams of ethanol per kilogram of body weight daily, similar to a human having one alcoholic drink.

  • The study was published on March 25, 2026 in the journal Royal Science Open Science.

The players

University of California, Berkeley

The research institution where the study was conducted.

Aleksey Maro

A doctoral student at UC Berkeley who worked on the study.

Robert Dudley

A biology professor at UC Berkeley who worked on the study.

Ammon Corl

A researcher who also worked on the study.

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What they’re saying

“Hummingbirds are like little furnaces. They burn through everything really quick, so you don't expect anything to accumulate in their bloodstream.”

— Aleksey Maro, Doctoral student

“They're burning it so fast, I'm guessing that they probably aren't suffering inebriating effects. But it may also have other consequences for their behavior.”

— Robert Dudley, Biology professor

“Somehow they are metering their intake, so maybe zero to 1% is a more likely concentration that they would find in the wild than anything higher.”

— Robert Dudley, Biology professor

What’s next

Researchers plan to further investigate how the presence of alcohol in nectar may influence the behavior and physiology of pollinating animals, and whether different species have developed adaptations to tolerate dietary alcohol.

The takeaway

This study highlights the unexpected ways in which alcohol is present in nature and how even small amounts may impact the complex relationships between plants, pollinators, and their environments. It underscores the need for continued research to understand the broader ecological implications of this phenomenon.